1. Field of the Invention
This disclosure generally relates to lifts, hoists and/or winches, more particularly to relatively low weigh capacity lifts, hoists and/or winches and/or even more particularly for lifts, hoists and/or winches for raising and lowering lighting equipment, especially in industrial environments.
2. Description of the Related Art
It is a common requirement for luminaries (see Definitions section) in industrial environments, theatrical venues and other large spaces, such as hotel and office atria and lobbies, arenas and gyms, convention centers, auditoriums and places of worship to be installed in positions and at elevations that make access difficult. For example, installation, focusing and regular maintenance are all somewhat problematical because the luminaire is installed high off the ground and must be accessed with the aid of with ladders, scaffolding, man lifts or other access equipment. The use of this access equipment can be impractical, physically demanding and/or unsafe. Additionally, such access equipment is bulky and needs to be stored, deployed, secured and removed for every use. This use of access equipment may also undesirably restrict use of the facility by blocking public spaces and/or thoroughfares.
One alternative approach to accessing luminaries is to provide the luminaire with a winch, hoist or other suspension system (see Definitions section) that allows the luminaire to be safely lowered to a point where access is more easily obtained.
Some conventional suspension systems are manually powered. For example U.S. Pat. No. 1,166,544 (“Prescott”) discloses an apparatus for raising and lowering chandeliers by manually turning cranks of a hoist. This approach has potential drawbacks both because of the manual labor required and also because of the space required.
Some conventional suspension systems are motorized. These motorized suspension systems have potential advantages over manual suspension systems in that a lower degree of operator proximity is generally necessary and less room is generally required for the installation. Some examples of conventional motorized lift systems are disclosed in the following US patents: (i) U.S. Pat. No. 2,609,170 (“Farrington”); (ii) U.S. Pat. No. 5,105,349 (“Falls”); (iii) U.S. Pat. No. 5,519,597 (“Tsai”); (iv) U.S. Pat. No. 5,556,195; (“Glebe”); (v) U.S. Pat. No. 7,293,762 (“Hoffend 1”); (vi) U.S. Pat. No. 6,634,622 (“Hoffend 2”); and/or (vii) U.S. Pat. No. 6,520,485 (“Soot”). Most, if not all, conventional motorized lift systems require the installation of the suspension system above the luminaire and, in many cases, above the ceiling structure. Although it may be possible to install such systems when a new building is being constructed, it may be difficult or impossible to add them once a building is in service.
A further problem and significant expense arises when an installation has multiple luminaries. Conventionally, multiple luminaries require the installation of multiple suspension systems. Also, there may be a need to suspend other suspended equipment in addition luminaries, such as loudspeakers, video monitors or displays, video or security cameras, seasonal decorations and signage. A further concern is the ease of getting power to such luminaries. Some conventional suspension systems disclose means for distributing power to an attached luminaries However, generally speaking, these conventional means of distributing power are not flexible, cannot accommodate multiple luminaries and/or cannot accommodate suspended electrical equipment other than the suspended luminaire(s).
FIG. 20 shows prior art nut tooth fastener hardware 500 including secured member 502; strut member 504; nut tooth member 512 and helical spring 508. The strut member includes two lips 506. The helical spring biases the nut tooth up into engagement with the two lips so that the nut tooth and spring can slide along and be positionally adjusted in the longitudinal direction of the strut member (that is, a direction in and out of the page with respect to FIG. 20). Secured member includes a through hole 503. The nut tooth member includes a tapped hole 514. A bolt (not shown) is inserted through the through hole and threadably engaged with the tapped hole to secure the secured member to the strut member. The nut tooth fastening hardware does not require any precise longitudinal direction alignment of the secured with respect to the strut member because of the longitudinal direction adjustability allowed by the geometry of the two lips of the strut member and the slidable nut tooth member and associated spring.
Description Of the Related Art Section Disclaimer: To the extent that specific publications are discussed above in this Description of the Related Art Section, these discussions should not be taken as an admission that the discussed publications (for example, published patents) are prior art for patent law purposes. For example, some or all of the discussed publications may not be sufficiently early in time, may not reflect subject matter developed early enough in time and/or may not be sufficiently enabling so as to amount to prior art for patent law purposes. To the extent that specific publications are discussed above in this Description of the Related Art Section, they are all hereby incorporated by reference into this document in their respective entirety(ies).